How fast do lice run? - briefly
Head lice crawl at roughly 1–2 cm s⁻¹ (about 0.03–0.07 mph), allowing them to move a few centimeters per minute across a host’s hair. Their locomotion is limited to short, slow bursts rather than sustained running.
How fast do lice run? - in detail
Lice are capable of moving at approximately 0.5 meters per minute (about 0.008 m s⁻¹). This speed results from rapid alternating leg motions that generate a crawling gait similar to that of other small arthropods.
Measurements come from high‑speed video analysis of live specimens on a glass surface. Researchers recorded frame‑by‑frame displacement, calculated average velocity, and confirmed consistency across multiple individuals. Reported values range from 0.3 to 0.7 m min⁻¹, with occasional bursts reaching 1 m min⁻¹ when disturbed.
Factors influencing locomotion include:
- Temperature: higher ambient temperatures increase metabolic rate, raising speed by up to 20 % between 20 °C and 30 °C.
- Substrate texture: smoother surfaces permit faster forward movement; rougher hair shafts reduce progress.
- Age and sex: adult females, carrying eggs, move slower (≈0.4 m min⁻¹) than unmated males (≈0.6 m min⁻¹).
Compared with other insects, lice are slower than houseflies (≈5 m s⁻¹) but faster than many mites (≈0.1 m min⁻¹). Their limited speed reflects a lifestyle confined to a host’s body, where rapid dispersal is unnecessary.
Understanding these dynamics aids in designing effective treatments, as mechanical removal must outpace the insect’s crawling ability to prevent re‑infestation.